Pump.



G. A. TAZ.

4 PUMR ARPLIGATION FILED NOV. 10, 1911,

Lg, Y ,PatentedAug 27, 1912.

l aesvaesa.

UNITED STATES PATENT ernten.

GLENN A. TOAZ, F DETRQIT, MICHIGAN.

Specification of Letters Patent. Patented Aug. 27, 191 2.

Applicationld. November 10, 1911. Serial No. 659,471..

To all whom 15mm/concern:

Beit known that I, GLENN A. ToAz, a citizen of the United States, residing at Detroit, county of Wayne, State of Michigan,

' automobile. I-secure this objectA in the device illustrated in the accompanying drawing, in which,

Figure 1, is a Vertical section of a pump 'embodying my invention. Fig. 2 is a detail sectional view showing a modified form of the same.

C, is the cylinder.

P, is a 'piston adapted to reciprocate in the cylinder C.

S, is the driving shaft, .A isa crank thereon and R a connecting rod between the piston P and crank A.

D, is an automatic valve through the port of which the air is discharged by the pump.

I, I indicate apertures formed through the wall of the cylinder C at such a position as to bev uncovered by the piston P toward the end of its downward stroke, the pump being shown as a vertical pump.

k is a chamber cast lntegral. with or formed adjacent to the cylinder C toward the upper or` discharge end thereof.

J, indicates apertures formed through the wall of the cylinder C toward the upper end thereof and connecting the interior of said cylinder with the chamber c.

K, is a cock turning in the chamber 7c adapted to put the apertures J into con- -nection with the outer air through a port j or to close said port shutting off the connection between the outer air and the apertures J.

The operation of the above described dej vice is as follows z-Power is communicated to the pump by rotating the shaft S which reciprocates the piston Pv by means of the crank A and connecting rod R. The cock K being closed, on the down strokepf the piston P a vacuum is drawn in the cylinder C, which is supplied by air from the atmosphere when the piston passes over and uncovers the apertures I. On the return stroke of the piston the apertures I are covered by the piston P and the air is compressed into the upper end of the cylinder 4and discharged .through the port ot' the valve D in the usual way. Should a smaller pressure, or less air, be required than will be furnished by the pump at its full stroke, in the operation just described, the cock K is turned to itsl open position, then, on the downward stroke ot the piston, a vacuum is drawn in the cylinder C above the apertures J until said apertures are uncovered by the lpiste-n P when atmospheric air rushes in to supply the vacuum. On its further downward stroke the piston P is Vfollowed by atmospheric pressure, the air passing through the apertures J, and such air is again discharged through said apertures until the same are closed by the piston P on its upward stroke, when the small quantity of air above the apertures J is compressed and discharged through the port of the valve D in the usual way.

There is always some clearance in a pump and therefore if the pump is left continuously running, it will not pump as high a pressure with the valves J open as with them closed, because the clearance remains the same in either case and and the quantity of air acted upon is less in the latter case. Ofecourse other ports might be supplied at different positions of the stroke of the piston J and the intermediate4 ports governed by cocks as the ports J are controlled in their action or an automatic inlet valve I; may be located in the head, as shown in By this device the eiective'length of the stroke of the pump piston may be. regulated.

What I claim4 is 1. In an vair pump, a cylinder, a piston adapted to reciprocate therein, and means for adjusting the effective length of the stroke of said piston by putting said cylinder into connection with the atmosphere during a part of the compression stroke of the piston.

2. In an air pump, a cylinder, a piston adapted to reciprocate therein, a plurality of inlet ports located at diii'erent points of the stroke of said piston, the'inlet port intermediate -in said stroke communicating with the atmosphere, and means for conadaptedto reciprocate therein, an inlet port, means for controllingthe opening through said port,`an opening communicating with said cylinder, means for'opening said opening at the commencement of and means for closing saidopening toward the end of the compression stroke of thepiston.

In 'testimony' whereof, I sign this specification in the presence of tWo Witnesses.

GLENN A. TOAZ. Witnesses:

STUART C. BARNES,

ELLIOTT J. STODDARD. 

